Window and door installation continues to be a time-consuming and labor intensive process. The prior art process can be most easily described in connection with wood frame structures, but the process remains similar for many other types of structures.
In a wood frame structure, the opening for the framed member, such as a window or door is first rough framed, with the framing members serving as the mounting members for windows and doors. The interior wall finishing for a room, such as wallboard, is usually affixed to the framing to form the interior wall of the room, and portions of wallboard may be used to finish the opening as well.
As shown in FIG. 1, which is labeled as prior art, window frames 10 typically have a flange 12, an interior face 14, a base 16 and other elements for supporting windows and screens. Apertures 18 are provided in the flange 12 for fastening the window in place. For purposes of this discussion, the base 16 of the top, bottom and side portions forming the frame of the window define the periphery of the window.
Typically, a window opening will be 1.3 cm (½ inches) larger on all sides than the frame of the window to be installed (excluding the flange 12 and other portions that depend from the base 16). The window is then set into the window opening, and paper or wood shims are inserted along the top, sides and bottom of the window frame to level and center it. The window frame is then fastened in place using screws or nails, and is caulked to seal against intrusion of wind and water. Materials such as wall board (gypsum board), wood and the like are then applied to the interior of the window opening and are butted up against the window frame to form the finished window opening.
Framing inaccuracies, bowing, twist or other defects in the framing of the window opening and the like can result in irregularities in the spacing between the interior of the window opening and the window frame. For example, if the window opening is in the configuration of a parallelogram, one side of the window frame may be nearly abutting the interior of the window opening at the bottom, and the other side of the window opening may be nearly abutting the frame at its top. In such case, the finishers installing the wall board or the like around the window opening may have to take time-consuming and labor-intensive remedial measures to ensure that the gypsum board or the like is squared and uniformly spaced with respect to the window frame and window.
Installation of pre-hung doors typically proceeds in like manner to window installation and encounters the same problems.
It is known to use an L-shaped shim plate to facilitate the finishing of the window opening. The first part of the shim plate extends into the window opening, and the second part of the shim plate lies in the plane of the wall. According to the known method, a plurality of nails or screws are partially sunk into the wood forming the window opening in a direction parallel to the plane of the window and extend generally perpendicular to the surface of the framing members that form the window opening. The heads of the nails or screws are left protruding inwardly into the window opening and form supports for the first portion of the sill plate.
The second portion of the sill plate, the securing flange, is then nailed in place to the side of the framing members forming the interior of the room. The wallboard, wood or other finishing materials are then positioned in contact with the first portion of the sill plate.
The process of setting the nails or screws to support the sill plate is time consuming and prone to errors. If the heads of the screws or nails are not set precisely, the sill plate will not be supported along its length at the proper position relative to the window. Furthermore, when the wallboard, wood or other finishing materials are nailed in place, and the nails are driven through the sill plate, the sill plate may be distorted and cause the finishing material to be improperly positioned.